The spinning of synthetic filaments by extrusion of certain materials through an orifice of some configuration is a generally accepted and well-known practice in textile manufacture. It is also known that certain desired physical properties may be attained for such synthetic filaments by spinning selected materials through spinneret orifice cross-sections that have been modified in some manner from round or nearly round transverse cross-sections that have been common for years. The cross-sections of filaments are designed for specific end uses, the formation of the cross-sections are in turn governed in part by the cross-sections of the spinneret orifices through which they are extruded.
Historically fibers used by man to manufacture textiles, with the exception of silk, were of short length. Vegetable fibers such as cotton, animal fibers such as wool, and bast fibers such as flax all had to be spun into yarns to be of value in producing fabrics. However, the very property of short staple length of these fibers requiring that the yarns made therefrom be spun yarns also resulted in bulky yarns having very good covering power, good insulating properties and a good, pleasing hand.
The operations involved in spinning yarns from staple fibers are rather extensive and thus are quite costly. For example, the fibers must be carded and formed into slivers and then be subsequently drawn to reduce the diameter and finally be spun into yarn.
The prior art discloses efforts to produce spun-like yarns from continuous filament yarns. See U.S. Pat. No. 4,245,001 for a more complete discussion of these efforts.
The present invention is directed to a spinneret that defines at least one spinneret orifice the planar cross-section of which defines an elongated slot having a plurality of wing member bar slots intersecting with the elongated slot at spaced intervals along the axial length thereof and having multiple intersecting body section bar slots intersecting with the elongated slot and intersecting with each of the other multiple intersecting body section bar slots at the elongated slot. The use intended is for melt spinning filaments and particularly for melt spinning multifilament, continuous filament yarns that, after subsequent processing, will have a spun-like character or a character similar to that achieved by spinning yarns from staple fibers but without involving all of the operations normally required for spinning yarns from staple fibers.
The term "wing member bar slot" serves to identify the bar slot responsible for creating lobes on the peripheral surface of the wing member of the filament cross-section extruded from the spinneret orifice.
The term "body section bar slot" serves to identify the bar slot responsible for creating lobes on the peripheral surface of the body section of such extruded filament cross-section.
The term "multiple intersecting," as applied to the body section bar slots, means that there is a multiple number (two or more) of such body section bar slots that not only intersect with each other but also such intersection occurs at the elongated slot, which is defined in the spinneret orifice cross-section.
The art discloses spinneret orifice cross-sections which show a plurality of bar slots intersecting with an elongated slot at spaced intervals along the axial length of the elongated slot, such as FIG. 12a in U.S. Pat. No. 3,156,085, with FIG. 12b illustrating the filament extruded from such spinneret orifice cross-section; and also such as the spinneret orifice illustrated in FIG. 5 of U.S. Pat. No. 3,109,195. U.S. Pat. No. 3,346,916 illustrates in FIG. 2 bar slots on one side of the elongated slot being offset with respect to the bar slots on the opposite side of the elongated slot. U.S. Pat. No. 3,156,085 also discloses a spinneret orifice being in the form of a star or having multiple intersecting bar slots such as illustrated in FIG. 9a. The filament cross-section extruded from such spinneret orifice is shown in FIG. 9b. None of the patents of which I am aware, however, disclose a spinneret orifice cross-section having a plurality of bar slots intersecting with an elongated slot at spaced intervals along the axial length of the elongated slot and also multiple intersecting bar slots intersecting with the elongated slot and intersecting with each of the other multiple intersecting bar slots at the elongated slot.